The approach taken by this proposal is to combine the PSMA drug with other radioactive drugs that also selectively target prostate cancer cells. One such class of drug targets the gastrin-releasing peptide receptors while another targets the luteinizing hormone releasing hormone receptors. By giving all three drugs together, we can increase the amount of radiation received by the tumor without giving too much radiation to any one part of the body. This is because these three different drugs go to different places in the body once it is injected, so not a lot of areas (except the tumor) gets irradiated by all three drugs. If this approach is proven to be successful, we will be able to increase the radiation dose give to tumors without causing additive worsening of side effects. Furthermore, this combinational approach could become the new paradigm for which all radioactive drugs are given in the future. We expect this approach to be ready for testing in humans in about 5 years.